Apparatus with a combination of a point light source and a single lens

ABSTRACT

An apparatus with a combination of a point light source and a single lens is provided. The present apparatus includes a point light source, a photodetector and a lens. The lens is placed in the same side of the point light source and the photodetector in order that the light emitting from the point light source is focused onto a target area of an object through the lens. The reflected light from the target area is focused onto the photodetector through the lens. The present apparatus can qualitatively and quantitatively monitor a content of a specific component of a tested solution. The geometric relationship of the point light source, the photodetector and the single lens can improve a measuring resolution of the present apparatus.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus capable of detecting asmall-size object or a small target area of an object, and moreparticularly to an apparatus with a combination of a point light sourceand a single lens.

2. Description of the Prior Art

The quantification of chemical and biochemical components in coloredaqueous fluids, in particular colored biological fluids such as wholeblood and urine and biological fluid derivatives such as serum and bloodplasma, is of ever-increasing importance. Important applications existin medical diagnosis and treatment and in the quantification of exposureto therapeutic drugs, intoxicants, hazardous chemicals and the like. Insome instances, the amounts of materials being determined are either sominiscule in the range of a microgram or less per deciliter or sodifficult to precisely determine that the apparatus employed iscomplicated and useful only to skilled laboratory personnel. In thiscase the results are generally not available for some hours or daysafter sampling. In other instances, there is often an emphasis on theability of lay operators to perform the test routinely, quickly andreproducibly outside a laboratory setting with rapid or immediateinformation display.

One common medical test is the measurement of blood glucose levels bydiabetics. The diabetic patients usually measure their blood glucoselevel from two to seven times a day depending on the nature and severityof their individual cases. Based on the observed pattern in the measuredglucose levels, the patient and physician together make adjustments indiet, exercise and insulin intake to better manage the disease. Clearly,this information should be available to the patient immediately.

In a method currently and widely used, a sample of fresh whole blood(typically 20˜40 μl) is placed on an ethylcellulose-coated reagent padcontaining an enzyme system having glucose oxidase and peroxidaseactivity. The enzyme system reacts with glucose and releases hydrogenperoxide. The pad also contains an indicator that reacts with thehydrogen peroxide in the presence of peroxidase to give a colorproportional in intensity to the sample's glucose level. Another popularblood glucose test method employs similar chemistry but in place of theethylcellulose-coated pad employs a water-resistant film through whichthe enzymes and indicator are dispersed.

In both cases the sample is allowed to remain in contact with thereagent pad for a specified time (typically one minute). Then in thefirst case the blood sample is washed off with a stream of water whilein the second case it is wiped off the film. The reagent pad or film isthen blotted dry and evaluated. The evaluation is made either bycomparing color generated with a color chart or by placing the pad orfilm in a diffuse reflectance instrument to read a color intensityvalue.

While the above methods have been used in glucose monitoring for years,they do have certain limitations. The sample size required is ratherlarge for a finger stick test and is difficult to achieve for somepeople whose capillary blood does not express readily.

In addition, these methods share a limitation with other simplelay-operator calorimetric determinations in that their result is basedon an absolute color reading, which is in turn related to the absoluteextent of reaction between the sample and the test reagent. The factthat the sample must be washed or wiped off the reagent pad after thetimed reaction interval requires that the user be ready at the end ofthe timed interval and wipe or apply a wash stream at the required time.The fact that the reaction is stopped by removing the sample leads tosome uncertainty in the result, especially in the hands of the homeuser. Overwashing can give low results and underwashing can give highresults.

Another problem that often exists in simple lay-operator calorimetricdetermination is the necessity for initiating a timing sequence whenblood is applied to a reagent pad. A user will typically have conducteda finger stick to obtain a blood sample and will then be required tosimultaneously apply the blood from the finger to a reagent pad whileinitiating a timing circuit with his or her other hand, therebyrequiring the use of both hands simultaneously. This is particularlydifficult since it is often necessary to insure that the timing circuitis started only when blood is applied to the reagent pad. Both of theprior methods require additional manipulations or additional circuitryto achieve this result.

Accordingly, it is an intention to provide means for monitor a contentof a specific component in a colored fluid such as a blood sample, whichcan overcome the drawbacks of the prior methods.

SUMMARY OF THE INVENTION

It is one objective of the present invention to provide an apparatuswith a combination of a point light source and a single lens, which canbe used to detect a small-size object or a small target area of anobject.

It is another objective of the present invention to provide an apparatuswith a combination of a point light source and a single lens, whichsatisfies requirements of light-weighted, miniaturized, and easilycarrying with.

It is still another objective of the present invention to provide anapparatus with a combination of a point light source and a single lens,in which the lens provides a light-focusing effect, therefore, a lightsource with highly light intensity is not necessitated.

It is yet another objective of the present invention to provide anapparatus with a combination of a point light source and a single lens,which is provided with a simple configuration and merely needs fewelements so that it is easily manufactured and production-cost saved.

It is a further objective of the present invention to provide anapparatus with a combination of a point light source and a single lens,which can be used to detect a specific component contained in a probezone of a test strip.

It is still a further objective of the present invention to provide anapparatus with a combination of a point light source and a single lens,which can be used to detect a specific component of a biologicalspecimen, and easily operated.

It is still a further objective of the present invention to provide anapparatus with a combination of a point light source and a single lens,in which the lens provides a light-focusing effect capable of improvingmeasuring resolution of the apparatus.

In order to achieve the above objectives of this invention, the presentinvention provides an apparatus with a combination of a point lightsource and a single lens. The present apparatus includes a point lightsource, a photodetector and a lens. The lens is placed in the same sideof the point light source and the photodetector in order that the lightemitting from the point light source is focused onto a target area of anobject through the lens. The reflected light from the target area isfocused onto the photodetector through the lens. The lens provides twicelight-focusing effects. The geometric relationship of the point lightsource, the photodetector and the single lens thus can improve ameasuring resolution of the present apparatus. The present apparatus isprovided with a simple configuration and few elements so as to save anoccupying space and conveniently carry with. The production cost is alsoreduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The objectives and features of the present invention as well asadvantages thereof will become apparent from the following detaileddescription, considered in conjunction with the accompanying drawings.

FIG. 1 is a schematic perspective view of a test strip; and

FIG. 2 is a schematic functional block diagram of a reflectanceinstrument according to a first preferred embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides an apparatus with a combination of apoint light source and a single lens. The present apparatus includes apoint light source, a photodetector and a lens. The lens is placed inthe same side of the point light source and the photodetector in orderthat the light emitting from the point light source is focused onto atarget area of an object through the lens. The reflected light from thetarget area is focused onto the photodetector through the lens. Thepresent apparatus can be used as a reflectance instrument for detectinga small-size object or a small target area of an object. A content of aspecific component contained in the object thus can be determined inaccordance with the reflectance of the light reflected from the objectdetected by the present apparatus. The present apparatus can be used todetect the reflectance of a light reflected from a colored area of atest strip occurring due to contact with a tested solution. A content ofa specific component of the tested solution can be determined inaccordance with the reflectance of the light reflected the colored areaof the test strip.

FIG. 1 is a schematic perspective view of a test strip 10 used formonitoring a specific component of a tested solution. The test strip 10includes a strip substrate 12 and a reagent pad 14. The reagent pad 14is attached onto a test surface of the strip substrate 12 with anadhesive 16. The reagent pad 14 includes an enzyme system and anindicator. The enzyme system contains an oxidase reacting with thespecific component of the tested solution to release hydrogen peroxideand a peroxidase to induce the hydrogen peroxide reacting with theindicator to produce a colored light-absorbing material. An opening 18is formed in a sample surface of the strip substrate 12 opposite to thetest surface. The tested solution is applied unto the reagent pad 14through the opening 18. When the enzyme system of the reagent pad 14contains glucose oxidase and peroxidase, glucose of a blood sampleapplied unto the reagent pad 14 through the opening 18 is catalyzed bythe glucose, oxidase to release hydrogen peroxide. Under catalyzed byperoxidase, the hydrogen peroxide reacts with the indicator to produce acolored light-absorbing material in the reagent pad 14 corresponding tothe test surface of the strip substrate 12. The glucose concentration ofthe blood sample is proportional to the color intensity, i.e. the shadeof the color, of the colored light-absorbing material. The coloredlight-absorbing material changes the reflectance of the light reflectedfrom the reagent pad 14. The glucose concentration of the blood samplecan be determined in accordance with the reflectance of the lightreflected from the colored light-absorbing material. When the enzymesystem of the reagent pad 14 contains cholesterol oxidase, whichcatalyzes cholesterol to release hydrogen peroxide. The test strip 10can be used to monitor a content of cholesterol in a blood sample.Therefore, the kind of the specific component of the tested solution tobe detected depends on the design of the enzyme system. In accordancewith the above-mentioned, the reflectance of the light reflected fromthe colored light-absorbing material of the reagent pad 14 is inverselyproportional to a content of the specific component. The presentapparatus detects the reflectance of the light reflected from thecolored light-absorbing material of the reagent pad 14. The content ofthe specific component of the tested solution is accordingly determined.

The present apparatus and applications thereof will be described indetail in accordance with preferred embodiments as follows.

FIG. 2 is a schematic functional block diagram of a reflectanceinstrument associated with a first preferred embodiment of the presentapparatus. The reflectance instrument associated with the presentapparatus includes a holder 21, a point light source 22, a photodetector23, a lens 24, an amplifier (AMP) 25, an analog to digital converter(ADC) 26, a microprocessor 27, a memory 28 and a display 29. The pointlight source 22 is disposed at a first end of the holder 21, and thephotodetector 23 is disposed at a second end of the holder 21. The firstend and the second end are on the same side of the holder 21. The lens24 is placed at the same side of the point light source 22 and thephotodetector 23 in order that the light emitting from the point lightsource 22 is focused onto a light-absorbing area 31 of an object 30through the lens 24. It is preferable that the object 30 is placed at afocal position of the lens 24. The reflected light from thelight-absorbing area 31 of the object 30 is then focused onto thephotodetector 23 through the lens 24. The light-absorbing area 31 of theobject 30 contains a colored light-absorbing material capable ofabsorbing the light emitting from the point light source 22. The colorintensity, i.e. the shade of color, of the colored light-absorbingmaterial is proportional to a content of a specific component causingthe colored light-absorbing material. As a consequence, the reflectanceof the light of the point light source 22 reflected from thelight-absorbing area 31 is inversely proportional to the content of thespecific component. Referring again to FIG. 1, the object 30 can be atest strip 10 having a colored light-absorbing area occurring due to aspecific component of a tested solution applied unto the reagent pad 14of the test strip 10 through the opening 18. The photodetector 23generates a response current in response to the light of the point lightsource 22 reflected from the light-absorbing area 31 of the object 30.In the present preferred embodiment, the point light source 22 can be alight emitting diode (LED), and the photodetector 23 can be aphotodiode, a charge-coupled device or a complex metal oxidesemiconductor sensor (CMOS sensor).

The response current generated from the photodetector 23 in response toa reflected light from the light-absorbing area 31 of the object 30 isconverted to an analog voltage by an amplifier (AMP) 25. The analogvoltage is converted to a set of digital signals through an analog todigital converter (ADC) 26, and then sent to a microprocessor 27. Themicroprocessor 27 serves the following control functions: 1) timing forthe entire system; 2) reading of the output of the analog to digitalconverter 26; 3) together with a program stored in a memory 28 tocalculate the reflectance measured at specified time intervals andstoring it in the memory 28; 4) calculating a concentration value of thespecific component corresponding to the light-absorbing area 31 of theobject 30. The concentration value is then displayed by a display 29,such as a liquid crystal display (LCD).

A second preferred embodiment of the present invention includes elementslike those of the first preferred embodiment except for the design ofthe point light source. In the second preferred embodiment, the pointlight source is designed to radiate a light with a first wavelength anda light with a second wavelength. The light with the first wavelengthcan be absorbed by the tested solution contained in the light-absorbingarea 31 of the object 30, and whether the sampling amount of the testedsolution is sufficient can be determined by the reflectance of the lightwith the first wavelength reflected from the light-absorbing area 31.For example, when the amount of the tested solution applied unto thelight-absorbing area 31 of the object 30 is insufficient, the presentapparatus detects the reflectance of the light with the first wavelengthmerely little less than the reflectance of the light with the firstwavelength upon that the tested solution is not applied unto the object30. For example, when the reflectance of the light with the firstwavelength is not less than a predetermined value, the analog to digitalconverter 26 could send one-bit digital signal “0” to the microprocessor27. The microprocessor 27 then sends an alarm signal to remind the userthe sampling amount of the tested solution is insufficient. When theamount of the tested solution applied unto the light-absorbing area 31of the object is sufficient, the reflectance of the light with the firstwavelength detected by the present apparatus is significantly decreasedcompared to that upon that the tested solution is not applied to theobject 30. For example, when the reflectance of the light with the firstwavelength detected by the present apparatus is less than thepredetermined value, the analog to digital converter 26 could sendone-bit digital signal “1” to the microprocessor 27. Then, themicroprocessor 27 controls the point light source 22 radiates the lightwith a second wavelength through the lens to focus unto thelight-absorbing area 31 of the object 30. The colored light-absorbingmaterial contained in the light-absorbing area 31 can absorb the lightwith the second wavelength. The colored light-absorbing material may becaused by the specific component of the tested solution applied unto theobject 30. Therefore, the content of the specific component can bedetermined in accordance with the reflectance of the light with thesecond wavelength detected by the present apparatus.

The lens 24 of the present apparatus utilized in the reflectanceinstrument provides twice light-focusing effect so as to improve themeasuring resolution of the reflectance instrument. Furthermore, thepresent apparatus has a simple configuration and fewer elements, thepurpose of cost down can be attained, and the requirements oflight-weighted, miniaturized, and conveniently carrying with are alsocomplied with.

The embodiments are only used to illustrate the present invention, notintended to limit the scope thereof. Many modifications of theembodiments can be made without departing from the spirit of the presentinvention.

1. (canceled)
 2. An apparatus, comprising: a light source configured toradiate light having a first wavelength, and to radiate light having asecond wavelength; a lens configured to focus each of the light havingthe first wavelength and the light having the second wavelength onto atest solution contained in a target area of an object; and aphotodetector configured to detect each of a first reflected light and asecond reflected light reflected from the test solution, wherein thefirst reflected light comprises at least a portion of the light havingthe first wavelength, and the second reflected light comprises at leasta portion of the light having the second wavelength.
 3. The apparatusaccording to claim 2, further comprising a processor configured todetermine a sampling amount of the test solution based on the firstreflected light.
 4. The apparatus according to claim 3, wherein theprocessor is further configured to determine a concentration of asubstance in the test solution based on the second reflected light. 5.The apparatus according to claim 4, wherein the substance is glucose andat least a portion of the test solution comprises blood.
 6. Theapparatus according to claim 4, wherein the substance is cholesterol andat least a portion of the test solution comprises blood.
 7. Anapparatus, comprising: means for emitting light having a firstwavelength, and for emitting light having a second wavelength; means forfocusing each of the light having the first wavelength and the lighthaving the second wavelength onto a test material in a target area of anobject; and means for detecting each of a first reflected light and asecond reflected light reflected from the test material, wherein thefirst reflected light comprises at least a portion of the light havingthe first wavelength, and the second reflected light comprises at leasta portion of the light having the second wavelength.
 8. The apparatusaccording to claim 7, wherein the test material is located at a focalposition of said means for focusing.
 9. The apparatus according to claim7, further comprising means for determining a sampling amount of thetest material based on the first reflected light, and determining anamount of a substance in the test material based on the second reflectedlight.
 10. The apparatus according to claim 7, wherein said means fordetecting is further configured to generate response currents based onthe first reflected light and the second reflected light.
 11. Theapparatus according to claim 10, wherein said means for detectingcomprises one or more of a photodiode, charge-coupled device, complexmetal oxide semiconductor sensor, or combinations thereof.
 12. Theapparatus according to claim 7, wherein the object comprises a teststrip and the test material comprises a solution.
 13. The apparatusaccording to claim 12, further comprising means for determining aspecific component in the solution based on the second reflected light,wherein the specific component reacts with an enzyme contained on thetest strip.
 14. The apparatus according to claim 7, further comprisingmeans for determining a concentration of glucose in the test materialbased on the second reflected light.
 15. The apparatus according toclaim 7, further comprising means for determining a concentration ofcholesterol in the test material based on the second reflected light.16. An apparatus, comprising: a light source configured to radiate lighthaving a first wavelength; a lens configured to focus the light havingthe first wavelength onto a tested solution; a photodetector configuredto detect a first reflected light reflected from the tested solution,wherein the first reflected light comprises at least a portion of thelight having the first wavelength; and a device configured to determinea sampling amount of the tested solution based on the first reflectedlight.
 17. The apparatus of claim 16 wherein: the light source isfurther configured to radiate light having a second wavelength; thephotodetector is further configured to detect a second reflected lightreflected from the tested solution, wherein the second reflected lightcomprises at least a portion of the light having the second wavelength;and the device is further configured to identify a specific component inthe tested solution based on the second reflected light.
 18. Theapparatus of claim 16, further comprising a holder having a first edgeconfigured to hold the light source, and having a second edge configuredto hold the photodetector.
 19. The apparatus of claim 18, wherein thelight source, photodetector, and lens are all located on a same side ofthe holder.
 20. The apparatus of claim 16 wherein the lens is configuredto focus the light having the first wavelength directly onto the testedsolution and focus the first reflected light directly onto thephotodetector.
 21. An apparatus, comprising: a holder; a light sourcelocated on a front side and at a first end of the holder; aphotodetector located on the front side and at a second end of theholder; and a single lens configured to focus light from the lightsource directly onto a test material in a target area, and focus areflected light reflected from the test material directly onto thephotodetector.
 22. The apparatus according to claim 21, wherein: thelight source is configured to radiate light having a first wavelengthand radiate light having a second wavelength; and the single lens isconfigured to focus each of the light having the first wavelength andthe light having the second wavelength onto the test material, and focuseach of a first reflected light and a second reflected light reflectedfrom the test material onto the photodetector, wherein the firstreflected light comprises at least a portion of the light having thefirst wavelength, and the second reflected light comprises at least aportion of the light having the second wavelength.
 23. The apparatus ofclaim 22, further comprising a device configured to identify a samplingamount of the test material based on the first reflected light, anddetermine a concentration of a component in the test material based onthe second reflected light.
 24. The apparatus of claim 23, wherein atleast a portion of the test material comprises blood and the componentin the blood is glucose or cholesterol.
 25. A method, comprising:emitting light having a first wavelength and emitting light having asecond wavelength; focusing each of the light having the firstwavelength and the light having the second wavelength onto a testsubstance; and detecting each of a first reflected light and a secondreflected light reflected from the test substance, wherein the firstreflected light comprises at least a portion of the light having thefirst wavelength, and the second reflected light comprises at least aportion of the light having the second wavelength.
 26. The method ofclaim 25, wherein the test substance is located at a focal position ofeach of the light having the first wavelength and the light having thesecond wavelength.
 27. The method of claim 25, further comprising:determining whether a sampling amount of the test substance is asufficient sampling amount or an insufficient sampling amount based onthe first reflected light; and determining a concentration of aparticular element in the test substance based on the second reflectedlight.
 28. The method of claim 27, wherein the particular element isglucose.
 29. The method according to claim 27, wherein the particularelement is cholesterol.
 30. A computer-readable storage medium havingcomputer-readable instructions stored thereon, which, when executed by acomputing device, configure the computing device to perform the stepsof: initiating emission of light having a first wavelength onto a testsolution; processing first test data, wherein the first test data isbased on a first reflected light reflected from the test solution, andthe first reflected light comprises at least a portion of the lighthaving the first wavelength; and determining whether a sampling amountof the test solution is a sufficient sampling amount or an insufficientsampling amount based on the first test data.
 31. The computer-readablestorage medium according to claim 30 wherein the instructions, which,when executed by the computing device, further configure the computingdevice to perform the step of generating an audio or visual notificationindicating whether the sampling amount of the test solution is thesufficient sampling amount or the insufficient sampling amount.
 32. Thecomputer-readable storage medium according to claim 30 wherein theinstructions, which, when executed by the computing device, furtherconfigure the computing device to perform the steps of: initiatingemission of light having a second wavelength onto the test solution;processing second test data, wherein the second test data is based on asecond reflected light reflected from the test solution, and the secondreflected light comprises at least a portion of the light having thesecond wavelength; and determining a concentration of a particularsubstance in the test solution based on the second test data.
 33. Thecomputer-readable storage medium according to claim 32 wherein theinstructions, which, when executed by the computing device, furtherconfigure the computing device to perform the step of displayinginformation based the concentration of the particular substance.
 34. Thecomputer-readable storage medium according to claim 33 wherein theparticular substance comprises glucose or cholesterol and at least aportion of the test solution comprises blood.